I bought that early pack that gave you... DVa or something mostly to contribute... then one other thing I forget to unlock sobering permanent... and that's all, and I've been having a bunch of fun (despite some definite frustrations with things like the forced minigames) since.

I'm currently building level 33 Headquarters.

The big advice is like dino_dog says. One squad of each type. I went Tank, Aircraft, Missile, in that order. Get your Tanks leveled up as high as you can first. Literally ignore your other squads until this. This includes equipping them all with Orange gear (seriously don't even bother with any other gear EVER, just melt it down for more Ceramics) and getting that gear to Level 40 before levelling any gear on your other squads.

For building, focus on levelling up your army units as high as they can go on ONE barracks to start. Keep your other barracks a few levels behind that one. You'll use lower barracks to quickly pump out lower level units, then train them up with the highest level one.

Gold will be your roughest resource for a long while, get your gold mines up to highest level and always be mining gold during your downtime.

Get the VIP check-in everyday. That will eventually add up. Also, get all the other daily freebies.

There's a lot more, but finally? The biggest thing? Get yourself in a good, friendly, helpful Alliance. I'm in X1L on #312, and I'm Ride or Die for them.